Son preference, sex selection and economic development

Sex ratios at birth in South Korea reached 116.5 boys per 100 girls in 1990, but have since declined. In 2007, sex ratios were almost normal, a development heralded as a sign that son preference and sex choice have vanished. However, normal sex ratios imply neither. We show that over the last 60 years, the relationship between sex ratios and parental status changed from negative to positive. This pattern, we argue, is consistent with a model where parents prefer sons and sex select – ultrasound and economic development accounting for the change in who chooses sons.